We propose to conduct an exploratory mixed method study of a symptom cluster intervention. The intervention will be tailored to provide symptom assessment and management for any of four target symptoms (fatigue, insomnia, pain, and depression) based on self-reported symptom severity that exceeds a specific threshold. Participants will also receive an adaptive dose of intervention in which the frequency and number of intervention sessions is determined by the severity of the symptoms reported in each intervention session. The aims of the study are to: 1) understand the characteristics of a symptom cluster as it changes over the course of a symptom intervention;2) characterize the intervention process including amount or dose of intervention and its effect on symptom outcomes;and pre- intervention (demographics, clinical characteristics, and personal attributes) and within- intervention factors (symptom severity changes and use of recommended interventions) that could predict symptom intervention dose and outcomes;and 3) in qualitative interviews, explore patient perceptions of the intervention experience. A final sample of 81 female breast cancer participants will be recruited into the study. Eligible individuals will be invited to complete a symptom diary during the first cycle of chemotherapy (phase 1). Entry into the intervention portion of the study (phase 2) will be limited to individuals whose symptom diary indicates that at least two of the target symptoms were elevated. Over four cycles of chemotherapy, intervention participants will receive a tailored symptom cluster intervention;the dose of intervention (number and frequency of sessions) will be adapted according to changes in symptom severity. Follow-up questionnaires to evaluate outcomes will be administered at the end of each chemotherapy cycle. A final interview will be conducted to explore participants'views of the symptom cluster intervention experience as it was modified by the symptom cluster intervention. Univariate and multivariate statistics as well as qualitative analysis will be used to examine the study aims. This research has the potential to inform our understanding of effective symptom cluster management;it will also guide future intervention trials that examine the efficacy of a tailored adaptive intervention. PUBLIC HEALTH RELEVANCE: Relevance to Public Health Cancer patients undergoing curative and palliative therapies are often bothered by multiple interrelated symptoms that interfere with their functioning and limit their quality of life. A symptom cluster that includes fatigue, insomnia, pain, and depression will be examined in the context of a tailored symptom intervention. The proposed exploratory study will broaden our scientific understanding of a symptom cluster as it changes in the context of cancer therapy and tailored symptom management in which the oncology nurse adapts the dose of intervention to patient need.